Matrix board

ABSTRACT

A novel electrical interconnection system is described. The system includes a novel multiple-bussed matrix board and associated hardware and assembly tools for use therewith. The matrix board includes a plurality of plated-through holes arranged in a coordinate system of rows spaced 0.100 inches on center, measured from aperture-to-aperture. Selected apertures are electrically connected to selected bus bars on one or the other side of the board.

This application is a divisional application of copending applicationSer. No. 314,578 now U.S. Pat. No. 4,455,749, filed Oct. 26, 1981,itself a division of application Ser. No. 64,372, filed Aug. 7, 1979,(now U.S. Pat. No. 4,330,684), which in turn was a continuation-in-partof application Ser. No. 864,457, filed Dec. 27, 1977, now abandoned.

Breadboarding of electronic circuits is a well known technique forproving the feasibility of a proposed electrical circuit. A conventionalprior art breadboard may consist of a flat, relatively stiff dielectricsheet material such as 1/16 inch thick fiber board or epoxy glass. Thedielectric sheet is perforated typically with apertures spaced on a 0.1by 0.1 inch grid so as to permit insertion or removal of leads fromelectrical and electronic components and jumper wires, e.g. so that anelectronic circuit can be laid out in order to test a new circuit and/orto facilitate changes, if necessary. Typically, the various componentsare laid out without regard to final location, the components areconnected together in a desired circuit path by jumper wires, and theindividual component leads and associated jumper wires are thenelectrically and mechanically connected, e.g. as by hand soldering inknown manner. Although this form of breadboard offers considerableadaptability, in that any component may be positioned virtually anywhereon the board, it will be appreciated that the task of inserting eachcomponent lead and wire in appropriate position, and of maintaining theleads and wire in position until they can be soldered is somewhatdifficult and laborious. Moreover, cutting the individual jumper wiresto required length and stripping the insulation from the cut wire endsis labor intensive and may add appreciably to the cost of breadboardinga circuit. Breadboarding techniques may also be employed in industry formanufacturing custom electronics assemblies, and for low-volumeproduction runs.

An improvement over conventional prior art breadboards is the so-calledmatrix or bus-bar board which is presently manufactured and availablecommercially from a number of manufacturers, including Augat, Inc.,(Attleboro, Mass.), Excel Products Co., Inc. (New Brunswick, N.J.),Vector Electronic Co., Inc. (Sylmar, CA.), and others. Such commerciallyavailable boards generally comprise a perforated board of dielectricmaterial such as epoxy glass with an electrically conductive metallicbus pattern on one surface of the board surrounding selectedperforations typically arranged for specific types and sizes ofcomponents (e.g. 6 to 20 pin 0.3 inch dual in-line packages (DIPs), or22 pin 0.4 inch DIPs, or 18 to 40 pin 0.6 inch DIPS, but not allsimultaneously). In this connection, it will be recognized that a boardperforated with apertures on a 0.1 by 0.1 inch grid will not readilyaccommodate a low resistance conductive metallic bus pattern betweenapertures, and consequently, a columnar arrangement of apertures spacedapart by a popular standard dimension is resorted to. In use, electricalcomponents are assembled onto such boards with their leads extendingthrough the board perforations. Also offered by the aforesaid and othermanufacturers are various sockets and mounting pins for mountingdiscrete components and jumper wires on the board. Typically suchsockets and pins are dimensioned so as to physically lock into the boardperforations, e.g. as by frictional engagement with wall areas of theboard defining the perforations. The discrete components may be affixedto the pins by soldering, while the jumper wires typically are affixedto the pins by a technique known in the art as wire-wrapping. (The term"wire-wrap" is a registered trademark of Gardner-Denver Company, GrandHaven, Mich., for a system for attaching jumper wires to asquare-sectioned terminal post by tightly wrapping a bared end of thewire around the post).

By suitably positioning the various components on the board, the numberof jumper wires required to complete a circuit may be substantiallyreduced. However, it should be noted that since the apertures arearranged on the board in pairs of columns spaced apart by one or morepopular standard dimensions, the layout of apertures dictates thepossible locations of interconnected components of differing sizes. As aconsequence, jumper wires carrying diverse signals may perforce havepaths which are longer than desirable and circuits on such boards maytherefore exhibit cross-talk. Typically, such boards frequently requireby-pass capacitors to be remote from the component to which they areconnected.

It will be appreciated that such matrix boards are used not only tobreadboard (i.e. form an experimental or test circuit) but also forshort production runs where it would not be commercially feasible tomanufacture the circuit in a standard commercial circuit board form.However, as noted, such boards readily accommodate only a limited numberof component sizes, and thus do not offer the adaptability of earlierstyle breadboards.

A primary object of the present invention is to provide an improvedinterconnection system for electrical and electronic circuits. A morespecific object is to provide an assembly system of the characterdescribed which, on the whole, is substantially simpler to use andtherefore more economical than prior art systems.

A further object is to provide an assembly system which reduces thenumber of jumper wires, and the lengths of critical jumper wires, whichmay be required for a given circuit while nevertheless accommodating awide variety of component sizes and styles, and thus offers theadvantages of relative simplicity, reliability, flexibility and low costas compared with prior art assembly systems.

Briefly described, the present invention consists, in one embodiment, ofan assembly system which comprises a novel matrix board in the form of asubstantially flat dielectric sheet or card having a unique coordinatepattern of plated-through apertures, and two or more electricallyinsulated voltage-distributing bus-bars formed on each of the oppositesurfaces of the card. Also forming a part of the preferred embodiment ofthe invention are novel assembly tools for facilitating insertion ofpins and components into apertures in the matrix board of the presentinvention.

Other objects and many of the attendant advantages of this invention areset forth or rendered obvious by the following detailed description. Theinvention accordingly comprises the apparatus possessing theconstruction, combination of elements and arrangement of parts, whichare exemplified in the following detailed description, and the scope ofapplication of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the presentinvention, reference should be made to the following detaileddescription taken in connection with the accompanying drawings in whichlike numerals depict like parts and wherein:

FIG. 1 is a top plan view of one surface of a preferred embodiment of amatrix board in accordance with the present invention;

FIG. 2 is a plan view of the opposite surface of the matrix board of theembodiment of FIG. 1;

FIG. 2A is a plan view of an alternate embodiment of the oppositesurface of the matrix board of FIG. 1;

FIG. 3 is an enlarged cross sectional view, in perspective, of aselected portion of the matrix board of FIGS. 1 and 2;

FIG. 3A is an enlarged cross sectional view, in perspective, of analternative embodiment of a selected portion of the matrix board ofFIGS. 1 and 2;

FIG. 3B is an enlarged cross sectional view, in perspective, of aportion of the matrix board of FIGS. 1 and 2A;

FIG. 4 is a top plan view of an assembly master for use with the matrixboard of FIGS. 1 and 2 to form a circuit in accordance with the presentinvention;

FIG. 5 is a top plan view of a location grid corresponding to the boardof FIG. 1 for use with the assembly master of FIG. 4;

FIG. 6 is a top plan view of a jumper for use with the matrix boards ofFIGS. 1, 2 and 2A;

FIG. 7 is a sectional view of the jumper of FIG. 6, taken along the line7--7 of FIG. 6;

FIG. 8 is a top plan view of a washer for use with the matrix board ofFIGS. 1 and 2A;

FIG. 9 is a sectional view of the washer of FIG. 8, taken along the line9--9 of FIG. 8; and

FIG. 10 is a perspective view, partially in section, of a portion of thematrix board of FIGS. 1 and 2A, viewed from the side illustrated in FIG.2A, showing the method of interconnecting components using the jumper ofFIGS. 6 and 7 and the washer of FIGS. 8 and 9.

Referring to FIG. 1 of the drawings, there is illustrated a preferredembodiment of the matrix board of the invention, indicated generally at20. Matrix board 20 comprises a substantially flat sheet or card 22 ofrigid, electrically insulating material such as a phenolic resin,glass-epoxy or the like.

As shown in FIG. 1, card 22 has a generally square or rectangular plan.Formed along one edge of card 22 is an elongated tab 24, the purpose ofwhich will become clear from the description following. A plurality ofelectrical conductors or bus bars are formed on a first flat surface 25of card 22. An important feature of the present invention is theconfiguration of the bus bars which has been designed to provide amaximum user flexibility for circuit building with a minimum requirementfor jumper wires. Thus as seen in FIG. 1, the conductors include a powerbus assembly in the form of first and second power conductors disposedperipherally on surface 25 of card 22: a right-side bus 28 which extendsadjacent the right side of card 22 and partially across top right-handedge of the card, and a left-side bus 30 which extends adjacent the leftside edge of the card and partially across the top left-hand edge of thecard. Importantly, buses 28 and 30 are separated from one another by asmall hiatus 31 located centrally at the top of card 22. For ease ofdiscussion the terms "left", "right", "top", "bottom" and "central" areused to signify relative positions on the surface of card 22 asillustrated in FIG. 1. It will be understood however that the left andright, and top and bottom, etc. bus positions can be reversed in keepingwith the present invention as will become clear from the discussionfollowing.

A ground plane bus assembly comprises a main conductor or carrier busbar 32 positioned on card 22 adjacent the top edge of the card andspaced and electrically separated from the top edge portions of powerbuses 28 and 30, respectively. A plurality of parallel spaced-apartfingers or branch bus bars 34 depend substantially in a normal directionfrom main carrier bus bar 32 parallel to the side edge portions of buses28 and 30. Branch bus bars 34 also are electrically connected to oneanother by one or more bridges 36 adajcent their ends remoted from mainbus bar 32.

Referring to FIG. 2 of the drawings, the opposite surface 38 of card 22carries a pair of electrically conductive power bus bars 40 and 42 whichare similar, but not identical to bus bars 28 and 30 but are registeredtherewith. Similarly, disposed on surface 38 is another ground planeassembly formed of main bus bar 44 corresponding to and registered withbus 32 and a plurality of branch bus bars 45 and an electricallyconnecting bridge 46 respectively corresponding to and registered withbars 34 and bridge 36.

It will be recognized that the ground plane assembly need not be limitedto a rectilinear grid. For some purposes, such as very high frequencyapplications, branch bus bars 45 and connecting bridges 46 may bebroadened to cover virtually all of the interior region of surface 38,thereby permitting relatively non-inductive ground paths. Such aconfiguration is shown as ground plane 47 in FIG. 2A. Ground plane 47 isdisposed on surface 38' of card 22' so as to extend between each andevery adjacent aperture 48', covering the region of surface 38'substantially opposite bus 32, bars 34, and bridge 36. As will be notedhereinafter, a more extensive ground plane 47 is made possible byconfiguring the plating of apertures 48' in a special way. In all otherrespects, card 22' is similar to card 22, as are surface 38' andapertures 48', with respect to surface 38 and apertures 48,respectively.

Matrix board 20 is provided with a plurality of plated-through holes orapertures 48. As may be seen by reference to FIG. 3, in its simplestform the plating is nothing more than a cylindrical lining 49 applied tothe interior of the aperature. An alternative embodiment, particularlysuited for use with card 22, is illustrated in FIG. 3A, where it may beseen that cylindrical lining 49A has been provided with connectingradial flanges 50 and 51, known as pads, disposed on surfaces 25 and 38respectively. Another alternative embodiment, this one particularlysuited for use with card 22', is illustrated in FIG. 3B, where it may beseen that lining 49B has been provided with a single connecting radialflange 50 disposed on surface 25. While, as will be described, a numberof apertures 48 will have their plating electrically connected toselected power and ground busses, the majority will not. It will beunderstood therefore that the extent of flanges 50 and 51 must be sochosen as to permit adequate electrical separation between flanges ofadjacent apertures and between flanges and adjacent busses. In the caseof card 22', surface 38' has disposed upon it massive ground plane 47,and the lack of flanges or pads connected to linings 49B and extendingover surface 38' permits ground plane 47 to extend closer to apertures48' than would be the case if a flange were provided on this surface. Inall other respects, linings 49A and 49B are similar to one another andto linings 49, as are apertures 48' to apertures 48.

As seen in FIGS. 1-2 the plated periphery of each of one or more ofapertures 48 are individually electrically connected to a respective oneof power buses 28, 30, 40 and 42, for example as at apertures 48A, 48B,48C and 48D, respectively. Similarly each ground plane assembly formedof buses 32 and 44 are respectively connected to the plating in certainapertures 48, for example, apertures 48E and 48F. It should be notedthus that one end of the cylinder formed by the plating in each of theseelectrically connected apertures is in contact with a bus on one surfaceof card 22 (e.g. apertures 48A in FIG. 1 in contact with bus 28 onsurface 25), the other end of the cylinder being exposed at the oppositesurface on card 22 but electrically discrete from all buses andapertures on that opposite surface (e.g. apertures 48A in FIG. 2).

As seen in FIGS. 1 and 2 of the drawings the majority of plated-throughapertures 48 are electrically discrete from one another and are alsoelectrically discrete from the various bus bars. However, an importantfeature of the present invention is the pattern in which plated-throughapertures 48 are arranged.

In accordance with the present invention, a plurality of apertures 48are arranged on board 22 in a pattern or array which includes a seriesof parallel vertical columns of apertures in which the vertical spacingof the apertures center-to-center is 0.10" from one another except thatwhere a column is interupted by bridge 36, the space across bridge 36between adjacent apertures in a column on each side is 0.20".

It will be seen from FIG. 1 that the array of such vertical columns canbe characterized according to the following discussion in which thecolumns are listed in numerical order starting from the first suchcolumn on the right hand margin of card 22 adjacent power bus 28. Theapertures are identified by the individual number order in each columnstarting from the top (located just below ground plane bus bar 32), andcounting down. The number of columns and apertures is merely examplary,and other numbers can readily be used. There are twenty-two columns ofapertures, thirty-eight apertures appearing in each of the first,second, twenty-first and twenty-second columns. Thirty-five aperturesappear in each of the third and twentieth columns. In the first column,the plating through of apertures nine, nineteen, twenty-nine,thirty-seven and thirty eight are directly electrically connected topower bus 28. The plating through aperture thirty-seven of the secondcolumn and apertures thirty-seven and thirty-eight of the twenty-firstcolumn are all directly electrically connected to adjacent ground planebranch bus bars 34. In column twenty-two, the plating through aperturesnine, nineteen, twenty-nine thirty-six and thirty-seven are eachdirectly electrically connected to power bus 30.

Each of the remaining columns (i.e. the fourth through nineteenth) hasthirty six apertures, the plating of none of which is electricallyconnected to any other aperture or bus bar on either side of the card.

The center lines of all of the columns are parallel to one another andare spaced from one another from right to left in FIG. 1, by a sequenceof interspaces between the first and eleventh columns by 0.10, 0.30,0.20, 0.10, 0.30, 0.20, 0.10, 0.30, 0.20 and 0.10 inches respectively.The order of spacing between the twenty second and twelfth columns isthe same sequence but reading from left to right. The center lines ofthe eleventh and twelfth columns are separated by an interspace of0.20". Branch bus bars 34 are disposed in all of the interspaces of 0.20and 0.30 inches except for the interspace separating the eleventh andtwelfth columns.

In addition, there is a row of ten apertures of the type hithertodescribed, lying approximately between ground plane bus bar 32 and thetop extensions of power buses 28 and 30, six of which apertures are notelectrically connected to any of the buses on surface 25 but rather tobusses on surface 38. Of the remaining four, two apertures 48A areelectrically connected to power bus 28 and two apertures 48B areelectrically connected to power bus 30.

Similarly, there is a row of apertures (the plating through each ofwhich is electrically connected to a respective ones of branch bus bars34) disposed across the card in a line running through the ninthapertures of columns four through nineteen inclusive. Similar rows ofapertures, electrically connected to respective ones of branch bus bars34, extend across the card along lines corresponding to the center ofapertures seventeen, twenty-five and thirty-three of columns fourthrough nineteen inclusive.

Also disposed in rows across the card are apertures lying in the 0.30"interspaces along lines corresponding to the centers of the eleventh,nineteenth, twenty seventh and thirty fifty apertures of columns fourthrough nineteen inclusive, the plating through the apertures of theserows however being electrically separated from connection with any ofbranch bus bars 34 in FIG. 1.

Lastly, there are a pair of rows of thirty-six plated-through apertureseach of the apertures in each such row lying along the lineperpendicular to the columns of apertures and spaced center-to-center by0.10" apart. Extending perpendicularly to the last mentioned two rows ofapertures are a corresponding number of electrical leads 52, preferablyplated onto tab 24, each respectively directly electrically connected tothe plating of a corresponding one of the apertures in the bottom-mostrow.

As seen in FIG. 2, a similar row of thirty six plated leads 54 is formedon the other surface 38 of tab 24, each of leads 54 being directlyelectrically connected to a corresponding one of the apertures in onlythe second row.

Referring further to FIG. 2 it will be seen that the arrangement ofother rows and columns of apertures 48 is (as expected in view of thefact that apertures 48 all extend through board 22 from surface 25 tosurface 38) identical to that of FIG. 1 except of course reversedleft-to-right. However the connections of apertures 48 to the variousbuses are somewhat different, for example as heretofore noted regardingapertures 48C, 48F and the like, so that those apertures 48 coupled onone side of the board to a bus are electrically discrete from any bus onthe other side of the board.

One skilled in the art will recognize the aforesaid configuration ofplated-through apertures and busses allows coupling or by-passing, asdesired, between the various busses on one or both surfaces of thematrix board 20 in any combination. Thus, for example, assuming powerbus assembly is selected as a power source for analog circuits,right-side bus 28 may be employed as the positive power supply and theleft-side bus 30 as the negative power supply (see FIG. 1). Then, asshown in FIG. 2, right-side bus 42 on the other side of the card cancomprise a source for logic circuitry and left-side bus 40 the negativepower for the logic.

Should the analog circuit require a larger power supply, for exampleside edge buses, e.g. 28 and 30, may be joined at the top center of thebus at 31 by a suitable jumper wire (not shown) to provide a positivesupply. A similar jumper in FIG. 2 will serve to join buses 40 and 42 ifdesired to provide the negative power supply, the entire card thencontaining analog circuitry. Other combinations will be obvious to oneskilled in the art.

Another advantage of the aforesaid configuration and spacing ofplated-through apertures at integral multiples (i.e. 1, 2 and 3) of0.10" on center is that the board lends itself to installation of moststandard electrical or electronic components, including standardintegrated circuit dual in-line packages (DIPs) and sockets, trim pots,coils, resistors, capacitors, transistors, etc., without the need forspecial component carriers. Not only can the board accommodate a varietyof sizes of components, but any component may be located virtuallyanywhere on the board, inasmuch as every region of the board canaccommodate all standard sizes of component. Thus, not only can maximumdensity packing be accomplished, but the layout of components of varioussizes may be made in accordance with the needs of the electroniccircuit, and not as the board dictates.

It will be understood by those skilled in the art that theplating-through of apertures 48 serves a number of functions. Such anaperture will accommodate a tight-fitting rectangular sectionedcomponent pin through the cold flow of the plating material, rather thanthrough the abrasion of the card 22 material, as would be the case withunplated apertures. Thus plated-through apertures may be used to secure,through friction, component pins of a given size even after theapertures have been repeatedly staked and unstaked during breadboarding.Further the plating serves as a heat sink, thereby protecting thematerial of card 22 from damage during any soldering or unsolderingoperations when components are secured or removed from component pinsstaked through the card. Further, the plating can serve as an electricalconductor, connecting component pins to selected busses. Finally, theplating itself may be secured by solder to a component pin, forming amore secure, albeit separable, mechanical and electrical bond. In all ofthese functions, it will be appreciated that flanged linings 49A and 49Bare superior to unflanged lining 49.

Referring now to FIGS. 6 and 7, there may be seen a jumper 240 made inaccordance with the principles of the present invention. Jumper 240comprises a substantially flat thin wafer 242 of rigid, electricallyinsulating material, such as a phenolic resin, glass-epoxy, or the like,which, in a preferred emodiment is substantially rectangular in planwith a length slightly less than 0.2 inch and a width somewhat under 0.1inch. An electrically conductive bus 244 is formed on one of the 0.2 by0.1 inch surfaces of wafer 242. Jumper 240 is provided with a pair ofholes or apertures 246 spaced 0.1 inch center-to-center and locatedalong the longitudinal axis of the jumper equidistant from thetransverse axis. Apertures 246 have diameters on the order of 0.04 inch,in order to readily accept component pin stems having a nominal crosssection 0.025 inch on a side. The apertures penetrate completely throughwafer 242 and bus 244.

FIGS. 8 and 9 illustrate a washer 248 for use with the presentinvention. Washer 248 is of a rigid electrically conductive material,such as brass, and may be solder plated, as may the electricallyconductive parts of the other components described herein, in order toaid in the assembly operations as will be described hereinafter. In apreferred embodiment, washer 248 is somewhat less than 0.1 inch inoutside diameter. Washer 248 is provided with a centrally located holeor aperture 250. Aperture 250 has a diameter on the order of 0.04 inch,in order to readily accept square-sectioned component pin stems havingnominal dimensions of 0.025 inch squared. Aperature 250 penetratescompletely through washer 248.

Turning now to FIG. 10, there may be seen a portion of an assembly ofelectronic components using the board, component pins, jumper, andwasher of the present invention. An IC (DIP) socket 252, shown in part,has been placed on surface 25 of card 22', with pins 254 extendingthrough selected apertures 48'. In an aperture 48' adjacent a selectedpin 254, a component pin 130, identified in FIG. 10 as pin 130A forclarity, has been provided, with its slotted head 142 on the same sideof the matrix board as socket 252. The selected pin 254 and adjacentcomponent pin 130A are connected together through jumper 240. The jumperis mounted with wafer 242 in contact with ground plane 47 and so locatedthat stem 256 of the selected pin 254 penetrates the jumper through oneaperture 246 while stem 132 of component pin 130A penetrates the jumperthrough its other aperture 246. The stems of these two pins aremechanically and electrically connected to bus 244 of jumper 240 bybeads of solder 258 between the stems and the bus. One of two electricalleads 260 of capacitor 262 is affixed, with solder, to slotted head 142of component pin 130A. Another component pin 130, indicated for clarityas pin 130B in FIG. 10, is provided to similarly attach to the otherlead 260. Component pin 130B is attached to card 22' in a manner similarto pin 130A and spaced apart from pin 130A a sufficient distance toaccommodate capacitor 262. The stem 132 of pin 130B passes throughaperture 250 of washer 248. Washer 248 is soldered, by beads 264, toboth stem 132 of pin 130B and ground plane 47.

It will be noted that pin 130A and the adjacent pin 254, while passingthrough card 22' and ground plane 47 and being electrically connectedtogether on the ground plane side of the card are neverthelesselectrically separated from the ground plane by the spacing between theground plane and plated through apertures 48' and by the insulationprovided between the ground plane and bus 244 by wafer 242.

More importantly, it will be noted that the pattern of apertures 48' hasallowed capacitor 262 to be placed immediately adjacent the IC terminalto which it is connected, the distance in the present case being 0.1inch, rather than the up to half an inch commonly encountered in priorart matrix boards. As a consequence, matrix boards made in accordancewith the present invention offer superior high frequency performance inthat they permit filter capacitors to be connected to other circuitelements through a low-inductance lead.

The matrix board disclosed above and as shown in FIGS. 1 and 2, isparticularly useful in a system which permits one to design a circuit onpaper and translate the design into finished, documented hardware witheffective configuration control throughout assembly and testing. Forprototypes and special systems, this means that breadboarding can beeliminated and hardware assembled and debugged in the finalconfiguration, even if extensive changes are anticipated. The resultwill be hardware ready for shipment supported by complete documentationfor instruction manuals and follow-on production. For breadboarding thismeans fast, economical and error free assembly of breadboards withminimum engineering supervision. During the design and debugging phasean accurate record of all changes can be kept and related to the testresults.

It should be noted that the high degree of adaptability of the matrixboard of the present invention is due to the large number of platedthrough apertures arranged in columns variously spaced apart. In any oneapplication, a large number of the apertures will not be used, and thedocumentation system used for planning or recording the layout mustprovide for the accurate depiction of the apertures used, while avoidingthe obscuration of detail through the representation of the large numberof unused apertures.

To this end there is provided as shown in FIG. 4 assembly master 220 inthe form of a translucent or transparent sheet which has thereon aprinted layout of the outline 222 of board 20, printed coordinate system224 for identifying locations on outline 222, and space 225 for awire-run list. Alternatively, the wire-run list may be complied on aseparate sheet. Also, as shown in FIG. 5, there is provided locationgrid 226 in the form of a separate sheet bearing outline 228 of board20, of the same dimensions as outline 222 and bearing coordinate system230 which is identical to system 224. Grid 226 also however includesindicia such as 232 corresponding to the location of each aperture onboard 20, and other indicia such as 234 corresponding to the portion ofbuses on board 20.

Master 220 is designed to be superimposed over grid 226 so that theportion of each electronic component can be marked on outline 222. Thus,highly professional layout drawings and wiring charts can be prepared bytechnicians. The resultant assembly drawing can then be given toproduction assembly type personnel for assembly of components and handwire-wrapping.

If there is access to an automatic wire-wrap facility, the necessaryprogramming can be accomplished directly from the assembly drawing runlist since this document and the card have been designed for automaticwire-wrapping.

The Parts List complements the assembly master and is organized toprovide complete information such as part descriptions, part numbers,quantities, etc.

Various changes may be made in the above processes and products withoutdeparting from the scope of the invention herein involved. For example,the matrix board may be lengthened, e.g. so that the various rows ofapertures include additional plated-through apertures. Obviously thevarious buses should be lengthened accordingly. It is therefore intendedthat all matter contained in the foregoing description shall beinterpreted in an illustrative and not in a limiting sense.

What is claimed is:
 1. In a combination with an electronic assembly forconnecting a bypass capacitor to a different electronic component withdependent leads, said component being mounted on a matrix board formedof an electrically insulating material provided with a plurality ofapertures arranged in a rectangular grid with centers spaced apart bydistances selected from the values which are integral multiples of about0.1 inch, said matrix board further being provided on a first surfacethereof with an electrically conductive ground plane path disposed so asto clear each of the majority of said apertures over a circular area,centered on each aperture, not exceeding about 0.1 inch in diameter; theimprovement including:first electrically conductive pin means forelectrically connecting leads of said electronic component to a selectedplurality of adjacent ones of said apertures so that said component ismounted adjacent the opposite surface of said board, said firstconductive pin means extending through said selected plurality ofapertures and beyond said first surface; second electrically conductivepin means for electrically connecting leads of said capacitor to aselected pair of said apertures adjacent said selected plurality ofapertures so that said capacitor is disposed adjacent said oppositesurface with said second conductive pin means extending through saidselected pair of apertures and beyond said first surface; a discreteconnector comprising:(A) an elongated electrically insulating waferhaving a length greater than about 0.1 inch and no longer than about 0.2inch and having a width less than about 0.1 inch, said wafer having apair of small circular holes penetrating therethrough and spaced about0.1 inch center to center, and (B) an electrically conductive busdisposed on one surface of said wafer and extending at least betweensaid pair of circular holes; said connector being assembled adjacentsaid first surface so that said insulating wafer is positioned betweensaid first surface and said electrically conductive bus, and so alignedthat a selected pin of said first conductive pin means and a selectedpin of said second conductive pin means respectively penetrate throughsaid pair of circular holes so as to make electrical contact with saidelectrically conductive bus; and a discrete pair of electricallyconductive, centrally apertured discs, each having an nominal outsidediameter no greater than about 0.1 inch but greater than that of saidcircular area; said discs being assembled in electrical contact withsaid ground plane and aligned respectively in contact with a selectedpin of said first conductive pin means and another pin of said secondconductive pin means.